Manufacture of azo dyestuffs



Patented May-19, 1931 UNITED STATES PATENT OFFICE KURT H. MEYER, OF MANNHIEIM, AND CUBT SCHUSTER, OF LUDWIGSHAFEN-ON-THE- RHINE, GERMANY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO GENERAL ANILINE WORKS, IN 0., OF NEW YORK, N. Y., A CORBORATION OF DELAWARE MANUFACTURE or AZO :oYEsrurrs No Drawing.

The present invention relates to the production of azo dyestuffs possessing valuable properties and to the production of dyeings on textile-material prepared from cellulose esters especially cellulose acetate silk.

The new azo dyestuffs, in accordance with our invention, are characterized by the presence of the mono-ethanol-amino group (-NH.CH .CH .OH) one or more of which group may be contained in the molecule of the dyestuff but inthe absence of sulfonic acid groups. The dyestufii' of the aforesaid type can be made according to the method suitable for producing azo dyestuffs, and the ethanol-amino group can be introduced into the moleculeeither by employing components containing such group or groups or by introducing the ethanol group into the amino group of the amino azo compound in such a way thatmono-ethanol-amino-derivatives are produced, but any other method suitable for preparing azo compounds containing the mono-ethanol-amino group may also be used. The said dyestufi's are excellently suitable for dyeing cellulose acetate silk from an aqueous solution or suspension, with or without an addition of Turkey red oil or similar dispersing agents or other auxiliaries in dyemg.

The invention is more fully explained by the following examples to which however the invention is not restricted. The parts are by weight.

' Example 1 27.6 parts of paranitraniline are diazotized in the usual manner and the solution of the diazonium compound is allowed to run, while cooling, into a solution prepared as follows: 27 .4 parts of mono-ethanol-aniline are mixed with 12 parts of glacial acetic acid diluted with 200 parts of water andmixed with 75 parts of crystallized sodium acetate dissolved in 200 parts of water. The dyestuff is separated out, sucked off and may be employed as a paste or in the powder form. It is readily soluble in hot water and dyes cellulose acetate silk beautiful orange red shades of very Application med August 31, 1925. Serial No. 53,741.

good fastness. the formula A red dyestufi' corresponding to the formula is obtained from 10.8 parts of mono-ethanolmeta-toluidine by dissolving them in 9 parts The dyestufi corresponds to of hydrochloric acid and 40 par-ts of water Ewample 2 30.4 parts of 3-nitro-4.1-toluidine are triturated with 90 parts of hydrochloric acid of 19 degrees Baum and mixed first with 300 parts of ice and afterwards, by portions, with 13.8 parts of sodium nitrite. The diazo solution so obtained is caused to run into a solution prepared from 27.4 parts of monoethanol-aniline, 12 parts of glacial acetic acid, 85 parts of sodium acetate and 500 parts of water. When the solutions are mixed, the liquor is neutralized with sodium carbonate and the dyestufi is separated by filtration. It may be made into a paste with an addition of Turke red oil which paste with hot water gives a ye-bath from which cellulose acetate silk is dyed orange. The dyestufi corresponds to the formula N 01 omC-rwrr-Orm-omcmom We claim:

1. As new articles of manufacture, azo coloring matters of the general formula:

wherein R represents a residue of the henzene series which is free from sulfonic acid groups.

2. As new articles of manufacture the azo dyestufis corresponding to the following formula:

@N-NONn-om-om-w in which the benzene radi'cles may be substituted by alkyl groups.

3. As new articles of manufacture the azo dyestuffs which correspond to the formula:

in which the benzene radicles may be substituted by alkyl groups. Y

4. As a new article of manufacture the red azo dyestufi which corresponds to the formula N0.-ON= QNm-cm-omon Hz 5. As a new article of manufacture a cellulose ester colored with the dye of claim 1.

. 6. The process of producing dyeings on cellulose esters which comprises applying to the cellulose ester an unsulfonated azo coloring matter derived from a diazotized para-nitroamino compound of the benzene series and a mono-ethanol-amino compound of the benzene series.

7. As a new article of manufacture a cellulose ester colored with the dye of claim 3.

In testimony whereof we have hereunto set our hands.

KURT, H. MEYER. CURT SGHUSTER. 

